Generally, the prior art has proposed temperature responsive electrical switch means which consisted of a housing portion containing a bimetal member movable, in response to sensed temperature, toward and away from a related fixed electrical contact or terminal as to thereby, in cooperation with such a fixed terminal, make and break an electrical circuit therethrough. In such prior art electrical switch assemblies, it was not an uncommon practice to have a cover or end wall member formed of dielectric material which, in turn, carried the fixed electrical contact. Often, such prior art fixed electrical contacts were threadably adjustable within the dielectric end cover as to thereby establish the desired calibration for the assembly.
Further, in such prior art switch assemblies, the threaded portion in the dielectric end cover were formed by machine tap which would cut the internal thread, within the dielectric end cover, which would cooperate with the external thread of the threadably adjustable fixed electrical contact or terminal.
A serious problem of such prior art switch assemblies resides in the fact that the dielectric material forming the end cover is, more often than not, relatively highly abrasive. Such abrasiveness, in turn, causes the taps to become quickly wornout resulting in internal thread conformations which will not accept, or at least properly accept, the external thread of the intended threadably adjustable fixed electrical contact or terminal. Consequently, there is a relatively high rate of scrapped dielectric end covers as well as a high usage rate of related thread taps. Such prior art structures, obviously, are relatively expensive to produce and because of the tap-wear, some of such prior art structures are, of necessity, close to the limits of acceptability. In some instances the prior art has suggested the use of nylon or glass-filled nylon material for forming the dielectric end cover; however, whatever benefits, if any, may have been found by the use of such material, in the fabrication of the switch assembly, the use of such materials is prohibited where the switch assembly and/or its environment may reach temperatures of about 250.degree. F. or more.
Accordingly, the invention has herein disclosed and described is primrily directed to the solution of the aforestated and other attendant and related problems of the prior art.